Add interfaces for a new compiler API.

tests/compiler/dart2js/bad_output_io_test.dart

Index: tests/compiler/dart2js/bad_output_io_test.dart
diff --git a/tests/compiler/dart2js/bad_output_io_test.dart b/tests/compiler/dart2js/bad_output_io_test.dart
index d2429f03b78ef029fb671f0291ec5f764e712670..ad2b0b9c5ee473cb129ee74996668de81d47e2f0 100644
--- a/tests/compiler/dart2js/bad_output_io_test.dart
+++ b/tests/compiler/dart2js/bad_output_io_test.dart
@@ -37,12 +37,14 @@ class CollectingFormattingDiagnosticHandler
    messages.add([message, kind]);
   }
 
-  void diagnosticHandler(Uri uri, int begin, int end, String message, kind) {
+  @override
+  void report(Uri uri, int begin, int end, String message, kind) {
     messages.add([message, kind]);
   }
 
+  @override
   void call(Uri uri, int begin, int end, String message, kind) {
-    diagnosticHandler(uri, begin, end, message, kind);
+    report(uri, begin, end, message, kind);
   }
 
   String prefixMessage(String message, Diagnostic kind) {